Vestibular-evoked myogenic potentials in central vestibular disorders

Abstract

Vestibular-evoked myogenic potentials (VEMPs) are short latency manifestations of vestibuloocular and vestibulocollic reflexes that originate from the utricle and saccule. Although cervical and ocular VEMPs have mostly been applied to peripheral vestibular disorders, the characteristics and the diagnostic values of VEMPs have been expanded to assess the function of the central otolithic pathways. In the central nervous system, the cervical VEMPs (cVEMPs) are mediated by the vestibular nuclei and uncrossed medial vestibulospinal tract descending in the lower brainstem and spinal cord. In contrast, the ocular VEMPs (oVEMPs) reflect the function of the vestibular nuclei and the crossed vestibulo-ocular reflex (VOR) pathways, mostly contained in the medial longitudinal fasciculus (MLF). Therefore, lesions involving the vestibular nuclei can present abnormalities of both cVEMPs and oVEMPs. The medullary lesions involving the descending MLF or the spinal accessory nucleus impair cVEMPs. In contrast, the lesions involving the MLF, the crossed ventral tegmental tract, oculomotor nuclei and the interstitial nucleus of Cajal can impair oVEMPs. Patients with unilateral cerebellar infarctions may show abnormal VEMPs especially when they have the ocular tilt reaction. Delayed responses of VEMPs are characteristic of multiple sclerosis (MS). Reduced VEMP responses can be observed in patients with vestibular migraine. VEMPs are useful in evaluating central as well as peripheral otolithic function that are not readily defined by conventional vestibular function tests, and can aid in detecting and localizing central lesions, especially silent brainstem lesions such as tiny infarctions or MS plaques.

Vestibular-evoked myogenic potentials in patients with severe obstructive sleep apnea

“…Accumulating evidence shows that cVEMPs combined with oVEMPs can detect a significantly higher percentage of abnormalities in the central vestibular pathway, despite some research groups reporting inconsistent results. 6,22 An intriguing finding in our study was that the rate of oVEMP wave acquisition (96.4%) was higher than that of cVEMP (86.9%) in the control group. This finding is in contrast to a previous study that investigated the relationship between VEMPs and OSAS and showed that the rate of obtaining oVEMP waves was lower than that of cVEMP.…”

“…oVEMP represents a crossed excitatory vestibulo-ocular reflex following activation of the utricular nerve that mainly passes through the medial longitudinal fasciculus from the upper brainstem to the midbrain. 6 Consequently, combined measurement of oVEMPs and cVEMPs should be a complementary approach for investigating clinically silent lesions in patients with OSAS. Accumulating evidence shows that cVEMPs combined with oVEMPs can detect a significantly higher percentage of abnormalities in the central vestibular pathway, despite some research groups reporting inconsistent results.…”

“…VEMPs are important as a type of potential diagnostic tool for detecting detrimental effects of the nervous system. [5][6][7] VEMPs are recorded from the muscles in response to vestibular stimulation. If potentials are recorded from the sternocleidomastoid (SCM) muscles, this is termed cervical VEMPs (cVEMPs), while if they are recorded from the extraocular muscles, this is termed ocular VEMPs (oVEMPs).…”

Evaluation of vestibular system using c-VEMP and o-VEMP in patients with relapsing-remitting multiple sclerosis

“…Thus, cervical and ocular VEMP tests are useful to assess the VOR and VCR pathways in MS patients. [16] In the cVEMP test, the same-side (non-crossed) medial vestibulospinal tract (extending to the spinal accessory core and vestibular nuclei) is evaluated. The oVEMP test explores the functions of the vestibular nuclei and VOR pathways via the contralateral…”

“…As the VCR and VOR arch pathways are located principally in the brainstem, the VEMP testing may yield information on brainstem lesions, although MRI shows no brainstem involvement. [6,[13][14][15][16] In the present study, we aimed to evaluate the role of cVEMP and oVEMP tests in the vestibular system in patients with relapsing-remitting MS (RRMS).…”